Oenothera havardii |
Oenothera acutissima |
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Havard's evening primrose |
flaming Gorge evening primrose |
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Habit | Herbs compact to sprawling, strigillose; from a taproot, lateral roots producing adventitious shoots. | Herbs perennial, subacaulescent or very short-caulescent, strigillose mostly along leaf margins and flower parts, also sparsely glandular puberulent, sometimes also sparsely hirsute distally; from a stout taproot, usually with several long, lateral roots often producing adventitious shoots. |
Stems | usually many-branched, sometimes unbranched, often twining among vegetation, sometimes rooting at nodes, 5–25(–70) cm. |
(when present) ascending, (1–)several–10, densely leafy, 1–2 cm. |
Leaves | in a basal rosette and cauline, basal usually quickly deciduous, (1–)2–5 × (0.2–)0.5–1.5 cm; petiole 0–0.6 cm; blade oblanceolate, linear-lanceolate to linear distally, margins few toothed to pinnately lobed to sinuate-dentate distally. |
primarily in a basal rosette, 7–14(–18) × (0.3–)0.5–1(–1.5) cm, moderately thick and stiff; petiole (1.2–)3–5 cm; blade linear to very narrowly elliptic, margins irregularly and coarsely dentate or pinnately lobed, apex long-attenuate. |
Flowers | 1–few opening per day near sunset; buds often twisted, free tips coherent; floral tube (37–)45–60(–65) mm; sepals (16–)18–26(–30) mm; petals lemon-yellow, fading orange-red to reddish purple, usually elliptic, sometimes oblanceolate, (18–)21–30(–32) mm; filaments 15–18(–22) mm, anthers red, 6–13 mm; style (55–)65–86(–94) mm, stigma exserted beyond anthers at anthesis. |
1–3 opening per day near sunset; buds with unequal free tips 1–3 mm; floral tube (53–)60–100 mm; sepals 26–50 mm; petals bright yellow, fading deep reddish orange, drying purplish brown, 28–50 mm; filaments 21–35 mm, anthers 9–11 mm; style 75–143 mm, stigma exserted beyond anthers. |
Capsules | woody, narrowly ovoid to ovoid, 4-angled, 8–13(–16) × 3–4 mm, apex tapering to a short sterile beak 2–3 mm, valves with a prominent, broad midrib and capsule appearing 8-ribbed, tardily dehiscent ca. 1/3 capsule length. |
leathery in age, oblong-oblanceoloid, narrowly winged, wings oblong, 1–2(–4) mm wide, broadest near apex, 14–18(–22) × 7–8 mm (excluding wings), apex abruptly constricted, dehiscent 1/4–1/3 their length, valve surface with inconspicuous veins; sessile. |
Seeds | 2–2.5(–3.3) × 1.2–1.5 mm, sometimes with a small wing at distal end or a raised ridge along one longitudinal margin. |
asymmetrically cuneiform, 2–2.5 mm. |
2n | = 14, 28. |
= 14. |
Oenothera havardii |
Oenothera acutissima |
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Phenology | Flowering Apr–Oct. | Flowering May–Jun. |
Habitat | In depressions, seasonally wet flats, stream banks, margins of irrigated fields, sandy or clay soil, among tufted grasses like Sporobolus wrightii, primarily in Chihuahuan Desert. | Restricted to sandy and gravelly, reddish, soil in seasonally wet sites, meadows, depressions, along arroyos, among rocks, in mixed conifer forests, sagebrush scrub. |
Elevation | 1300–2000 m. (4300–6600 ft.) | 1800–2400(–2600) m. (5900–7900(–8500) ft.) |
Distribution |
AZ; TX; Mexico (Chihuahua, Durango, Sonora, Zacatecas) |
CO; UT |
Discussion | Oenothera havardii ranges from Brewster and Presidio counties, Texas, and Cochise County, Arizona, south to Durango and Zacatecas, Mexico. W. L. Wagner (1984) found that O. havardii is self-incompatible and vespertine. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Oenothera acutissima is known only from the vicinity of Manila, eastern Uinta Mountains, Daggett and Duchesne counties, Utah, east to areas in and near the foothills of the Douglas and Blue mountains, in Uinta County, Utah, and Moffat County, Colorado. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Hartmannia havardii, H. palmeri | O. flava var. acutissima |
Name authority | S. Watson: Proc. Amer. Acad. Arts 20: 366. (1885) — (as havardi) | W. L. Wagner: Syst. Bot. 6: 153, fig. 1. (1981) |
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